Determination of key intermediates for homogeneous water-gas shift reaction and hydrocarbonylation of ethylene to diethyl ketone catalyzed by the ‘Pd(OAc)2-PPh3-CF3COOH/H2O’ system

Зудин, В. Н.; Chinakov, V. D.; Nekipelov, V. M.; Rogov, Vladimir A.; Likholobov, V. A.; Yermakov, Yu. I.

doi:10.1016/0304-5102(89)80080-x

Cited by 91 publications

(52 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Palladium complexes are also able to catalyze the WGSR via formation of Pd(II) Á/ hydride intermediate. In such a reaction coordination of water to the Pd-center has been proposed [10,11]. On the basis of these results we proposed that a Pd Á/hydride species plays a major role in the catalysis.…”

Section: Introductionmentioning

confidence: 79%

Synthesis, characterization and X-ray structure of trans-[Pd(COOCH3)(H2O)(PPh3)2](TsO), a possible intermediate in the catalytic hydroesterification of olefins (TsO=p-toluenesulfonate)

Cavinato

Vavasori²,

Toniolo³

et al. 2003

Inorganica Chimica Acta

View full text Add to dashboard Cite

The complex trans -[Pd (COOCH 3 (II) have been obtained by re-crystallization of I in methanol. The structure of the complex has been determined by X-ray analysis. It shows a slightly distorted square planar conformation around the central palladium. The coordinated water molecule and the clathrated methanol form a contact with the uncoordinated TsO ( anion, suggesting hydrogen bond interaction. Since I is a possible intermediate in the catalytic hydroesterification of olefins, its catalytic activity in the hydroesterification of ethylene has been tested at 100 8C under 45 atm of a 1/1 mixture of ethylene and CO in methanol as solvent, also in the presence of PPh 3 and TsOH. Without addition of PPh 3 and TsOH, I affords to traces of methylpropionate together with Pd(0) complexes and Pd metal. The same results are obtained when complex I is tested in the presence of PPh 3 , except that in this case formation of palladium metal is avoided. Using the system I/PPh 3 /TsOH 0/1/6/8, a TOF (mol of ester/mol Pd+h) of 1800 h)(1 is obtained. We propose that the role of the acid TsOH is to favor the formation of a Pd Á/ hydride intermediate and/or to reactivate the Pd(0) species, stabilized by the excess of PPh 3 , via an oxidative addition of the acid. Since the acid does not favor the formation of Pd Á/alkoxy species we suggest that complex I plays only a minor role in catalysis and that this occurs via a Pd Á/hydride species. #

show abstract

Section: Introductionmentioning

confidence: 79%

Synthesis, characterization and X-ray structure of trans-[Pd(COOCH3)(H2O)(PPh3)2](TsO), a possible intermediate in the catalytic hydroesterification of olefins (TsO=p-toluenesulfonate)

Cavinato

Vavasori²,

Toniolo³

et al. 2003

Inorganica Chimica Acta

View full text Add to dashboard Cite

show abstract

“…Upon increasing the concentration of H 2 O, the formation of a cationic aqua-complex is favored also by the increasing of the dielectric constant of the reaction medium, which favors the separation of the charges. A Pd(II)-aqua-species is not a polymerization initiating species, but upon reacting with CO it can be transformed into an active Pd-H + species through a reaction strictly related to the Water Gas Shift [44][45][46] (step 2a). HCOOH may also activate the precursor through formation of a Pd-OC(O)H + species followed by ␤-hydride elimination and evolution of CO 2 (step 2b).…”

Section: Proposed Catalytic Cyclementioning

confidence: 99%

Terpolymerization of propene and ethene with carbon monoxide catalyzed by [PdCl2(dppf)] in HCOOH–H2O as a solvent [dppf=1,1′-bis(diphenylphosphino)ferrocene]

Vavasori¹,

Ronchin²,

Toniolo³

2010

Applied Catalysis A: General

View full text Add to dashboard Cite

a b s t r a c tThe [PdCl 2 (dppf)] complex efficiently catalyzes the terpolymerization of propene and ethene with carbon monoxide in HCOOH-H 2 O as a solvent, when H 2 O concentration ranges between 50 and 65 molar %. The productivity, the melting temperature and the viscosity average molecular weight of the terpolymer depend on the propene concentration and on the reaction time.The NMR analysis of the polymer composition indicates the presence along the chain mainly of ethene-CO units together with a low percent of propene-CO units.A reaction mechanism is proposed and discussed.

show abstract

“…Monocarbonylated products form through the so called ''hydride'' mechanism, which involves the insertion of the olefin into a Pd-H bond with formation of a Pd-alkyl bond, followed by the insertion of CO into the Pd-alkyl intermediate with formation of a Pd-acyl species, which undergoes alcoholysis or hydrolysis to the ester or the acid with reformation of the Pd-H species starting the catalytic cycle [8][9][10][11]. DEK forms when the insertion of a second molecule of ethene into the Pd-acyl bond occurs with formation of a Pd-alkylacyl intermediate, followed by protonolysis [12][13][14]. If the Pd-alkylacyl intermediate undergoes successive multiple sequential insertions of CO and ethene the process of chain growing proceeds through the intermediate formation of b-and c-chelates till termination occurs with formation of cooligomers or of PK [1][2][3]15].…”

Section: Introductionmentioning

confidence: 99%

Synthesis, characterization and X-ray structure of [Pd(SO4)(dppp)]·H2O, a catalyst for the CO-ethene copolymerization [dppp=1,3-bis(diphenylphosphino)propane]

Cavinato

Vavasori

Toniolo

et al. 2005

Inorganica Chimica Acta

View full text Add to dashboard Cite

The title complex has been synthesized by first reacting dppp with Pd(AcO) 2 in acetone and then with NaHSO 4 in water. It has been characterized by IR, NMR and X-ray diffraction studies. The 31 P NMR spectrum in DMSO shows a singlet at 16.62 ppm indicating that the two P atoms are equivalent and that the sulfate anion is weakly coordinating. The X-ray structure shows that the Pd atom is surrounded in an almost regular square planar environment by the two P atoms and by two O atoms of the sulfate anion and that the neutral complex is accompanied by a water molecule of crystallization. The Pd-P distances (2.217(1) and 2.233(1)) and the P-Pd-P angle (90.78(3)°) are close to those found in other complexes where the chelating diphosphine is the same. Also the Pd-O distances and the O-Pd-O bond angle are comparable to those of other relevant chelating ligands.In MeOH, the title complex, in combination with H 2 SO 4 , catalyses the CO-ethene copolymerization. The productivity reaches a maximum upon increasing the H 2 SO 4 /Pd ratio up to ca. 470 (7650 g of polyketone/g Pd h at 90°C and 45 atm, CO/ethene 1/1). The viscosity of the polyketone passes through a maximum of 0.95 dL/g in m-cresol when the above ratio is ca. 100. It has been proposed that acid promotes the copolymerization process by destabilizing the b-and c-chelates intermediates involved in chain growing process, thus favoring the insertion of the monomers. At relatively high acid concentration the lowering of productivity and viscosity suggests that the sulfate anion competes with the monomers for the coordination to the metal center.In H 2 O-CH 3 COOH as a solvent the productivity strongly depends on the H 2 O/CH 3 COOH ratio, as it passes through a maximum of 12 000 g polymer/g Pd h in the presence of ca. 60% of H 2 O. The productivity is significantly lower than that found when the acetate and chloride analogues are used (27 000 g polyketone/g Pd AE h). Thus, it is likely that the sulfate anion assists significantly the copolymerization process even though the concentration of CH 3 COOH/CH 3 COO À is much preponderant.

show abstract

Determination of key intermediates for homogeneous water-gas shift reaction and hydrocarbonylation of ethylene to diethyl ketone catalyzed by the ‘Pd(OAc)2-PPh3-CF3COOH/H2O’ system

Cited by 91 publications

References 13 publications

Synthesis, characterization and X-ray structure of trans-[Pd(COOCH3)(H2O)(PPh3)2](TsO), a possible intermediate in the catalytic hydroesterification of olefins (TsO=p-toluenesulfonate)

Synthesis, characterization and X-ray structure of trans-[Pd(COOCH3)(H2O)(PPh3)2](TsO), a possible intermediate in the catalytic hydroesterification of olefins (TsO=p-toluenesulfonate)

Terpolymerization of propene and ethene with carbon monoxide catalyzed by [PdCl2(dppf)] in HCOOH–H2O as a solvent [dppf=1,1′-bis(diphenylphosphino)ferrocene]

Synthesis, characterization and X-ray structure of [Pd(SO4)(dppp)]·H2O, a catalyst for the CO-ethene copolymerization [dppp=1,3-bis(diphenylphosphino)propane]

Contact Info

Product

Resources

About